Good afternoon. You can not request a public defender for him. The PD will be appointed when he goes before the Judge, to answer to the violation of probation. What you can do is retain him private counsel, who can start working on the case, see him n jail and try and get his released, if there is no bond set on him. When a person violates, they can either admit to the violation or deny it. If they deny it, then a final hearing will be held and the State will have to show a violation. They also will have to answer to the new charge, if this was not a technical violation, so often times, if there is no defense, a plea deal with include both the violation and new charge.